# -*- coding: utf-8 -*-
"""
Created on Fri Oct 14 17:45:13 2016
@author: Kirby Urner
"""
print("{:=^40}".format("< Exhibit 1: scoping controls >"))
from random import choice
def add_tricks(cls):
"""
choice(tricks) maintains access to add_tricks namespace,
what's known as a "closure" (like a "bottled" space)
cls.tricks = [...] would also work
"""
tricks = ["play dead", "roll over", "sit up"]
def do_trick(self):
return choice(tricks)
cls.do_trick = do_trick
return cls
@add_tricks
class Animal:
"""
Decorate a class with a function, end up with a
new second inheritable method
"""
def __init__(self, nm):
self.name = nm
class Mammal(Animal):
"""Lets teach an old dog some new tricks... """
pass
# Animal = add_tricks(Animal) <-- 'no decorator' alternative
obj_1 = Animal("Rover")
print(obj_1.name, "does this trick:", obj_1.do_trick())
obj_2 = Mammal("Trixy")
print(obj_2.name, "does this trick:", obj_2.do_trick())
print("{:=^40}".format("< Exhibit 2: str() vs repr() >"))
class Airport:
"""
Clarifying the relationship between str() & repr()
"""
def __init__(self, three_letter_code): # birth!
self.code = three_letter_code
def __str__(self):
return "Airport w/ code: " + self.code
def __repr__(self):
return "Airport('{}')".format(self.code)
portland_or = Airport("PDX")
newark_nj = Airport("EWR")
print(portland_or) # __str__
print(repr(portland_or)) # __repr__
print("{:=^40}".format("< Exhibit 3: scoping controls >"))
brand = "Cheery Deary" # who can overwrite
def outer():
brand = "Deco Echo"
def inner():
# global brand
nonlocal brand # reference enclosing scope
brand = "Oompa Loompa" # could be local
print("inner:",brand)
inner()
print("outer:",brand)
outer()
print("Global:", brand)
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